Cellular and castellated steel members are usually made starting from a hot-rolled Ⅰ-section member, of which the web is thermally cut according to a certain pattern. Subsequently, the obtained halves are welded together. Thus, a member with a larger depth and with circular or hexagonal web openings placed regularly along its length is obtained. In the past, it has been shown for hot-rolled I-section members that residual stresses have a considerable detrimental influence on the global buckling resistance, which is mainly governed by the compressive residual stresses in the flanges. While it was expected that similar effects play a role for cellular and castellated members, it was yet unknown to which extent the residual stresses in these members would be modified by the fabrication procedure. As a result, it was difficult to correctly predict the buckling resistance of cellular or castellated members using numerical simulations. As part of a more extensive research about the global buckling resistance of cellular and castellated members, the authors have measured the residual stresses in a number of castellated and cellular member specimens. The results of these measurements are summarized in this paper and the influence of different modified residual stress patterns on the weak-axis flexural buckling and lateral torsional buckling resistances is determined. Based on these results, a residual stress pattern valid for castellated and cellular members will be proposed. It will be shown that the fabrication procedure has a considerable effect on the original residual stresses, which will influence the buckling resistance detrimentally.
展开▼
